The present invention relates generally to the field of electric motors and methods and apparatus for manufacturing electric motors. More particularly, the invention relates to a novel technique for separating stator winding conductors of a randomly wound stator.
Electric motors of various types are omnipresent in industrial, commercial and consumer settings. In industry, such motors are employed to power all types of rotating machinery, such as pumps, conveyors, compressors, fans and so forth, to mention only a few. Conventional alternating current electric motors may be constructed for single or multiple phase operation, and are typically specifically designed to operate at predetermined synchronous speeds, such as 3600 rpm, 1800 rpm, 1200 rpm and so on. Such motors generally include a stator, comprising a multiplicity of coils, surrounding a rotor which is supported by bearings for rotation in the motor frame. In the case of AC motors, alternating current power applied to the motor causes the rotor to rotate within the stator at a speed which is a function of the frequency of alternating current input power and of the motor design (i.e., the number of poles defined by the motor windings and rotor resistance). In DC motors power is similarly applied, and the speed of the motor may be controlled in a variety of manners. In both cases, however, a rotor shaft extends through the motor housing and is connected to elements of the machinery driven by the electric motor.
In conventional electric motors, conductors, known as stator windings; are routed through parallel slots formed around the inner periphery of a metallic core. The stator windings are electrically connected in groups around the stator core to form electro-magnetic coils. The coils establish the desired electro-magnetic fields used to induce rotation of the rotor. The number and locations of the windings in the stator core generally depends upon the design of the motor (e.g., the number of poles, the number of stator slots, the number of winding groups, and so forth). Each winding coil includes a number of turns of wire that loop around end or head regions of the stator between the slots in which the winding coil is installed. Multiple conductors are wound in each slot in a randomly wound stator. Following installation in the slots, the coils in each group are generally pressed into a bundle at either end of the stator. The stator windings are connected to electrical wiring that is routed from the stator to a wiring or conduit box located on the outside of the motor through corresponding holes in the motor frame and the conduit box.
While conventional motor manufacturing equipment and methods have been generally satisfactory in many applications, they are not without drawbacks. For example, each stator winding must be separated from the other stator windings so that the stator windings may be electrically connected in the proper configuration. Wiring the stator windings in the wrong configuration will decrease the performance of the motor, if the motor is able to operate at all. However, separating the stator windings by hand is time-consuming and increases the cost of manufacturing the motor.
There is a need, therefore, for an improved technique for separating the stator windings of an electric motor after they have been wound on the stator. There is a particular need for a technique that provides the equipment and/or a method for automatically separating the stator windings of an electric motor during the electric motor manufacturing process.